A system stream defined by MPEG2 standard (ISO/IEC 13818-1) is already known as a method for compressing video in a low bit rate. Three types of streams, a program stream (PS), a transport stream (TS), and a PES stream, are defined in the system stream.
In addition, a system stream defined by MPEG4 standard (ISO/IEC 14496-1) is also already known as a method for compressing in a lower bit rate. Five types of streams, a program stream (PS), a transport stream (TS), an H223 stream, an RTP stream, and an MP4 stream, are defined in the system stream.
On the other hand, an optical disc such as DVD-RAM, MO has become to be significant as a video recording medium replacing a magnetic tape. FIG. 16 shows a construction of a conventional AV data recording and reproducing apparatus 300 for video with a DVD-RAM disc. In FIG. 16, a program stream is generated from input signals from a video signal input section 100 and an audio signal input section 102 by a compressing section 301, respectively, and the generated program stream is written in a DVD-RAM disc 131 through a recording section 320 and a pickup 130. In reproduction, the program stream read through the pickup 130 and a reproducing section 321 is decoded into a video signal and an audio signal by a decoding section 311, and the decoded video and audio signals are provided to a video signal output section 110 and an audio signal output section 112. The compressing section 301 can compress a signal in MPEG2 and in a lower rate than MPEG2. The decoding section 311 can decode a signal compressed in MPEG2 or a signal compressed in the lower rate than MPEG2.
In recording, a recording control section 341 controls the recording section 320. In addition, according to an instruction of the recording control section 341, a continuous-data-area detecting section 340 checks availability of a sector managed by a logic block management section 143, and detects a physically continuous available area. When a recorded video signal file is deleted, the recording control section 341 controls the recording section 320 and the reproducing section 321, and performs deleting process.
Thus, conventionally, the AV data recording and reproducing apparatus 300 reproduces a signal compressed in MPEG2 for example, and a user plays video and audio by connecting it to a display apparatus such as a TV.
Recently, a portable video player capable of playing video in a further lower bit rate has been introduced. While, such a portable video player 400 has a similar construction to the AV data recording and reproducing apparatus 300, a battery (not shown) is used in the portable video player 400 as a power source to be carried for playing.
Accordingly, for example, when a user records a broadcast program, in the case that a user views the broadcast program on a TV screen, the user records a video signal and an audio signal of the program onto a recording medium with compressing in MPEG2 (hereinafter referred to as “record in MPEG2”), for example. In addition, in the case that the user views the program on the portable video player 400, the user records the video signal and the audio signal with compressing in a low bit rate lower than in MPEG2 (referred to as “record in a low bit rate”). Additionally, both of the AV data recording and reproducing apparatus 300 and the portable video player 400 have a resuming function which, after interrupting playing video, allows to play the subsequent video on the apparatus that interrupted playing the video (for example, see Japanese Laid-Open Patent Publication KOKAI No. 2001-344874).
On the other hand, there is a case that the user records the program in a low bit rate at first to play the program on the portable video player 400, and then he or she plays the recorded program on the portable video player 400 outdoors and stops playing it. After that, the user may play the subsequent video from the some midpoint in his or her home. In such a case, the program is recorded onto the recording medium only in the low bit rate. Therefore, there was a problem that the user cannot play it in high-resolution image quality even if he or she plays it on a TV screen much larger than the display of the portable video player 400.
In addition, there is the other thinkable case where the user records a program in MPEG2 to play the program on a TV in his or her home, and then he or she plays the recorded program in the home and stops playing it at some midpoint. After that, the user may play the subsequent video from the some midpoint on the portable video player 400 outdoors. In such a case, the program is recorded onto the recording medium only in MPEG2. Therefore, the portable video player 400 should decode the signal recorded in MPEG2. The signal recorded in MPEG2 requires much larger power consumption as compared with the signal recorded in a low bit rate when read or decoded. Accordingly, there was a problem where a battery of the portable video player 400 tends to exhaust quickly.
Thus, since a playing mode is specified when a program is recorded, it is difficult that the program is played suitably according to conditions (image quality, a bit rate, power consumption, etc.) of each playing mode when the previously specified playing mode is changed.